As you have already read, an approach refers to the teory of the language. There are many different approaches. All of those approaches were held by different prponents. Here, you will find four theoretical orientations to clasify them.

Structural: Those approaches based on structural theory tend to believe language rules know as grammar and syntax may be memorized to reach a high proficiency level. 

Cognitive: In this type of approaches, students are the center of the learning and teachers look how to teach effectively. Here, the knowedge are learned and cannot be predetermined. 

Psychological: Here, proponents develops those approaches linken on social or psicological theories. Psycological approaches take into account aspects like motivation, learning styles, predisposition and more. 

Functional/Communicative: Those approaches focus on spoken language rather than written language. Also, take carefully grammar rules but as a tool for effective communication

As you have already read, an approach refers to the theory of the language. There are many different approaches. All of those approaches were held by different proponents. Here, you will find four theoretical orientations to classify them.

Structural: Those approaches based on structural theory tend to believe language rules know as grammar and syntax may be memorized to reach a high proficiency level. 

Cognitive: In this type of approach, students are the center of the learning and teachers look at how to teach effectively. Here, knowledge is learned and cannot be predetermined. 

Psychological: Here, proponents develop those approaches linked with social or psychological theories. Psychological approaches take into account aspects like motivation, learning styles, predisposition, and more. 

Functional/Communicative: Those approaches focus on spoken language rather than written language. Also, take carefully grammar rules but as a tool for effective communication

Check this video to make sure what an approach is and identify all of its implications like activities, materials, and learners' and teachers' roles.

Stevie, D. (2020). 10 Flexible Language Teaching Approaches That Are Totally Approachable. FluenU. https://www.fluentu.com/blog/educator/language-teaching-approaches/

Duran, K. (2014). The Nature of Approaches and Methods in Language Teaching. https://www.youtube.com/watch?v=sb_UR5VxC4k